1. Field of the Invention
The present invention relates generally to a plasma display panel, in particularly to a device of increasing the efficiency of heat dissipation of the addressing ICs of the plasma display panel and the method thereof.
2. Description of the Related Art
A conventional plasma display panel (PDP) mainly has a substrate, a back plate mounted behind the substrate, a plurality of tape carrier packages (TCP) disposed at a margin of the substrate, across the back plate to connect with a printed circuit board (PCB), each of TCP is disposed with an addressing integrated circuit (addressing IC), a frame cover a margin of the panel and a back plate mounted at a back of the substrate.
While the plasma display panel works, the temperature thereof will increase and if the panel has a greater resolution, it generates greater heat. The heat is generated mainly by the addressing ICs. The addressing IC is sensitive to temperature that if the addressing IC is working in a high temperature, it will be unstable. The conventional panel is disposed with a radiator to dissipate the heat of the addressing ICs.
U.S. Pat. No. 6,198,222 discloses a heat dissipating device, which provides two fans in an inlet and an outlet of the frame to enforce the heat dissipation. This device increases the size of the panel and the cost of fabrication, so that it is not an optimal solution.
Another heat dissipating device is taught by U.S. Pat. No. 6,288, 489 and U.S. Pat. No. 6,617,767 and it uses the back plate to be the heat sink. The back plate is made of aluminum and a heat-conductive rubber sheet is disposed at between the back plate and the substrate. The heat-conductive rubber sheet has a well property of heat conduction to conduct the heat generated from the addressing ICs to the back plate. The back plate has a larger area to dissipate heat. Although the device does not use fan to force dissipating heat, it also has a good efficiency of heat dissipating.
The main drawback of the second device is that the dissipating heat of the back plate is mainly from the substrate rather than from the addressing ICs. In other words, the heat generated by the addressing ICs is conducted to the substrate, and then conducted to the back plate, it is an indirect dissipating heat function.
To overcome aforesaid drawback, a new heat dissipating device is provided. As shown in FIG. 1, the device has a substrate 20 and an aluminum frame 21 is mounted at a margin of the substrate, a plurality of addressing ICs 22 are disposed at between a TCP 23 and the frame 21, an inner heat-conducting sheet 24 is provided at between the TCP 23 and a back plate 26 to bond the TCP 23 on the back plate 26 and an outer heat-conducting sheet 25 is provided at between the addressing ICs 22 and the frame 21. As a result, the heat of the addressing ICs 22 is directly dissipated by the frame 21 via the outer heat-conducting sheet 25.
Aforesaid invention has a well heat dissipation efficiency and it takes less space. But the present plasma display panel is required for a smaller and lighter panel, the heat dissipating device still has to be improved. Such as how to increase the efficiency of heat dissipation without having to change the layout and the sizes or sharps of the substrate, the TCP and the addressing IC.